Rover 75 Diesel - Cooling Fan Box Unknown loose cable - Page 2

zickleer · 28th July 2019, 14:28

Here's a quick drawn diagram

https://ibb.co/N3QhSgt

Red wire from relay box spliced into 2, 1 goes to resistor and the other 1 is the detached/grounded. The resistor then continues the journey in a grey wire routed back into the relay box. (the loop is in Relay 1, there are a total of 3 relays in the relay box)

Thanks for the speedy reply Simon, 👍

SD1too · 28th July 2019, 14:29

Quote:

Originally Posted by zickleer

Does the resistor need to be connected to the fan motor?

Yes. The resistor is wired in series with the motor.

But there must be further changes yet to be found because the detached wire means that the motor would never run but it does the opposite!

Can you trace the two wires coming out of the motor please and tell me where they go.

Simon

zickleer · 28th July 2019, 14:36

Thanks for the heads up Simon, I haven't actually removed the entire fan assembly.
I just propped up the left hand side of the fan casing and popped out the relay box. As the fan is running, hence was thinking the fault lies with the relay rather than loose connections. But alas all 3 relay works. Will get back to you soon as possible as it's 1030pm right now, rather dark to carefully remove the fan assembly, and I am I might accidentally cracked the air con gas piping on the other side 😅

Appreciate your help once more Simon 👍

Quote:

Originally Posted by SD1too

Yes. The resistor is wired in series with the motor.

But there must be further changes yet to be found because the detached wire means that the motor would never run but it does the opposite!

Can you trace the two wires coming out of the motor please and tell me where they go.

Simon

SD1too · 28th July 2019, 14:42

OK, you're in Kuala Lumpur yes?

You can't see the motor wires then without dismantling? I was hoping to have an answer for you this afternoon.

By the way, you have a two speed system so the third relay with no wired connections is out of circuit.

Simon

zickleer · 28th July 2019, 14:51

Yeaps that's right, I think I might be the one of the few ones still running a Rover 75 in Malaysia 😁

I tend to make mistakes when it's late and dark hehe, better not risk it. Will report back on the motor connections Simon, no worries on the reply, anytime when you are free 👍

SD1too · 28th July 2019, 14:55

Quote:

Originally Posted by zickleer

I tend to make mistakes when it's late and dark hehe, better not risk it.

Very sensible.

I'll check-in with you when the sun has risen here tomorrow morning then!

Simon

Arctic · 28th July 2019, 18:34

Quote:

Originally Posted by zickleer

https://ibb.co/ZdtQsMn
https://ibb.co/ChfX3Nv

I am really sorry to take your Sunday rest time, Arctic.

Here's the photos, I just snipped off the old resistor and then added some short wires to the gold resistor as the existing wire is too short(after being snipped off) and thus making it bent at an awkward angle. The addition aly short wires(in blue) prevented the awkward angle bent.

Should I ground the butchered cable? Or does it goes to 1 of the white socket's 2 terminals? Clueless at this point 😅

I think my next step to solve the forever spinning fan (never stops throughout whole journey until about 5-10 seconds after engine is switched off) would be diagnosing the coolant temperature sensor.

Thanks Arctic

Quote:

Originally Posted by SD1too

Apologies Steve for jumping in but this is a fascinating puzzle!

The thick red wire exiting the control box was earthed at the open chassis box section but, as you say, became detached during dismantling. This earthed wire by-passed the control box relays.

Zickleer, please confirm to which colour wires you have connected the resistor and where those wires go. I can't tell from the photographs.

Simon

HI Simon
No problem two heads better than one as always, yes I suspected from the photo's and the wires being bolted to the chassis leg that it as been bypassed, I also have a suspicion that the fan motor & blades are from another car if you look at the photo carefully>

1

2

3

It looks like the fan needs to be removed from the car so we can rectify the wiring so it works as it should, I am also wondering was it bypassed because the PCB is not working ? therefore they have made it run continually.

Photo of what the control box should look like inside.

4

5

Zeekleer when you get time see if you can remove the fan from the car and we can go from there.

SD1too · 29th July 2019, 06:52

Quote:

Originally Posted by Arctic

I also have a suspicion that the fan motor & blades are from another car if you look at the photo carefully ...

Well spotted Steve.

My plan was to get the existing fan wired correctly then we can see if the PCB is working.

Simon

Arctic · 29th July 2019, 09:20

[QUOTE=SD1too;2751062]Well spotted Steve.

Quote:

My plan was to get the existing fan wired correctly then we can see if the PCB is working.

Hi Simon.
I agree that is best way forward, it would be best if the fan was off the car, as I can see from the photo's that the brown & black larges wires coming from the fans loom have been attached to the chassis leg of the car

therefore that will need correcting too.

This could turn out to be a big job maybe even requiring a short look from the fan motor to the main loom, I have a feeling that the original fan was a four wire 3 speed fan and the wiring as been chopped to maybe try and get a 2 speed fan from another car to work.

SD1too · 29th July 2019, 11:30

Quote:

Originally Posted by Arctic

... I can see from the photos that the brown & black larges wires coming from the fans loom have been attached to the chassis leg of the car ..

Hi Steve,

I haven't been able to identify these connections. Is it possible for you to highlight it on the photos please?

Simon

28th July 2019, 14:42	#14
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,382 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	OK, you're in Kuala Lumpur yes? You can't see the motor wires then without dismantling? I was hoping to have an answer for you this afternoon. By the way, you have a two speed system so the third relay with no wired connections is out of circuit. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

28th July 2019, 14:28	#11
zickleer Newbie mg Join Date: May 2014 Location: kl Posts: 13 Thanks: 10 Thanked 1 Time in 1 Post	Here's a quick drawn diagram https://ibb.co/N3QhSgt Red wire from relay box spliced into 2, 1 goes to resistor and the other 1 is the detached/grounded. The resistor then continues the journey in a grey wire routed back into the relay box. (the loop is in Relay 1, there are a total of 3 relays in the relay box) Thanks for the speedy reply Simon, 👍

28th July 2019, 14:51	#15
zickleer Newbie mg Join Date: May 2014 Location: kl Posts: 13 Thanks: 10 Thanked 1 Time in 1 Post	Yeaps that's right, I think I might be the one of the few ones still running a Rover 75 in Malaysia 😁 I tend to make mistakes when it's late and dark hehe, better not risk it. Will report back on the motor connections Simon, no worries on the reply, anytime when you are free 👍